Compressor having noise reducing apparatus

ABSTRACT

In a compressor having a noise reducing apparatus capable of minimizing noise propagated to the outside of a casing, by constructing a bottom cap of a casing as a double wall structure and naturally filling oil inside the casing into the double wall, high frequency noise occurred at the bottom cap side can be efficiently excluded, and accordingly a noise absorption efficiency can be maximized.

TECHNICAL FIELD

[0001] The present invention relates to a compressor used for an airconditioner or a refrigerator, etc. using a refrigerant cycle, and inparticular to a compressor having a noise reducing apparatus which iscapable of minimizing noise propagated to the outside of a compressor.

BACKGROUND ART

[0002] Generally, a compressor is for converting mechanical energy intocompression energy of a compressive fluid, among them a freezingcompressor is largely divided into a reciprocating compressor, a scrolltype compressor, a centrifugal type compressor and a rotation typecompressor, etc.

[0003] Vibration and noise may occur in the operation of thosecompressors, herein, high frequency noise occurs mainly due to frictionsound between a pressure pulsation sound and parts, and the occurrednoise passes the compressor and is propagated to the outside. Thepropagated noise is a main factor increasing operation noise of an airconditioner or a refrigerator, etc.

[0004] Hereinafter, a noise propagation phenomenon in the operation of acompressor and problems thereof will be described on the basis of aZ-compressor disclosed by the present inventor.

[0005]FIG. 1 is a longitudinal sectional view illustrating aZ-compressor in which the present inventor has disclosed in Korea patentApplication No. 10-1999-42381 in Oct. 1, 1999 and the Patent Laying-OpenGazette (Patent 2001-35687) published by Korean Intellectual PropertyOffice in May 7, 2001.

[0006] First, the Z-compressor will be described. The Z-compressor canbe regarded as a rotation type compressor, it includes an electric motorpart 20 placed inside a sealed casing 10 and generating a rotationalforce and a compressing part 30 sucking, compressing and discharging afluid by the rotational force generated in the electric part 20.

[0007] The electric motor part 20 consists of a stator 22 and a rotor 23same as a general electric motor.

[0008] The compressing part 30 includes a cylinder assembly 31 fixed atthe lower portion of the casing 10 and forming a compression space inwhich a sucked fluid is compressed, a rotational shaft 25 transmitting arotational force generated in the rotor 23 of the electric motor part20, a Z-plate 35 combined with the rotational shaft 25, rotating with itand dividing the compression space of the cylinder assembly 31 into afirst space V1 and a second space V2, a first and a second vanes 38 and39, etc. respectively contacted to the upper and the bottom surfaces ofthe Z-plate 35 by receiving an elastic force from springs 36, 37 anddividing each space V1, V2 into a suction region and a compressionregion in the rotation of the Z-plate 35.

[0009] Herein, the cylinder assembly 31 includes a cylinder 32, a firstand a second bearing plates 33, 34 respectively fixed to the upper andthe bottom surfaces of the cylinder 32 and forming the compressionspaces V1, V2 with the cylinder 32.

[0010] Particularly, in the Z-plate 35 fabricated as a disk shape in aplane view according to the prior art, the outer circumfenrentialsurface slide-contacts to the inner circumferential surface of thecylinder 32, the side surface is formed as a sine wave curve cam surfacehaving the same thickness from the inner circumferential surface to theouter circumferential surface. The surface consisting of a top deadcenter R1 rotates by contacting to the bottom surface of the firstbearing plate 33, and the surface consisting of a bottom dead center R2rotates by contacting to the upper surface of the second bearing plate34.

[0011] In the meantime, a reference numeral 14 is a suction path inwhich a fluid flows in the casing 10 and the cylinder 32, and areference numeral 15 is a discharge pipe in which a fluid is dischargedto the outside of the casing 10. Reference numerals 40 and 41 aredischarge mufflers for lowering discharge noise.

[0012] The operation of the Z-compressor will be described.

[0013] When the rotational shaft 25 rotates by the driving force of theelectric motor part 20, the Z-plate 35 combined with the rotationalshaft 25 of the cylinder assembly 31 sucks, compresses and dischargesthe fluid by simultaneously rotating with the rotational shaft 25.

[0014] In more detail, the first space V1 placed at the upper portion ofthe Z-plate 35 is divided into a suction region and a compression regionon the basis of the top dead center R1 of the Z-plate 35 and the firstvane 38, and the second space V2 placed at the lower portion of theZ-plate 35 is divided into a suction region and a compression region onthe basis of the bottom dead center R2 of the Z-plate 35 and the secondvane 39. In that state, by rotating the Z-plate 35, the top dead centerR1 and the bottom dead center R2 of the Z-plate 35 move, and accordinglyvolume of the suction region and the compression region of each space isvaried.

[0015] Herein, the first vane 38 and the second vane 39 reciprocate inthe opposite direction each other at the cam surface height of theZ-plate 35.

[0016] Accordingly, the fluid is simultaneously sucked into each suctionregion V1 s, V2 s of the first and the second spaces V1, V2 through thesuction path 14 and gradually compressed, when the top and the bottomdead centers R1, R2 of the Z-plate 35 reach a discharge start point, thecompressed fluid is simultaneously discharged to the outside of thecylinder assembly 31 through each discharge path (not shown) of eachspace V1, V2. After that, the fluid passes each discharge muffler 40, 41and the casing 10 and is discharged to the outside through a dischargepipe 15.

[0017] In the operation of the Z-compressor, lots of noise may bepropagated to the outside of the casing 10 due to fraction soundoccurred between the pressure pulsation sound and the parts in the fluiddischarge, FIG. 2 is a noise radiation distribution view illustratingnoise propagated to the outside of the casing 10 in the operation of theZ-compressor.

[0018] In more detail, in the casing 10, on the basis of the cylindricalbody 11, the upper cap 12 is combined at the upper portion, and thelower cap 13 is combined at the lower portion in order to seal theinternal space. As depicted in FIG. 2, noise propagated to the outsideof the casing 10 in the operation of the compressor mainly occurs at thelower portion of the casing 10 at which the lower cap 13 is placed.

[0019] In the meantime, in order to reduce noise occurred at the lowerportion of the Z-compressor, when a thickness of the lower cap 13 shownin FIG. 3 is increased from 3.5 mm to 4.5 mm, as depicted in FIG. 4, aTL (transmission loss) is increased about 2 dB.

[0020] Accordingly, there is insignificant noise reducing effect. Itmeans noise propagated to the outside in the operation of the compressorcan not be efficiently reduced by only increasing a thickness of thelower cap 13.

[0021] Therefore, in all compressors using the sealed casing includingthe above-described Z-compressor, technologies which are capable ofmaximizing a noise reducing quantity by reducing noise propagated to theoutside of the compressor without lowering a performance of thecompressor have been required.

TECHNICAL GIST OF THE PRESENT INVENTION

[0022] In order to solve the above-described problems, it is an objectof the present invention to provide a compressor having a noise reducingapparatus which is capable of minimizing noise propagated to the outsideof the compressor.

[0023] In addition, it is another object of the present invention toprovide a compressor having a noise reducing apparatus which is capableof maximizing a noise reducing quantity by efficiently preventing noisepropagation at the lower portion of a compressor at which comparativelylots of high frequency noise occurs.

[0024] In addition, in a compressor using a Z-plate, it is anotherobject of the present invention to provide a compressor having a noisereducing apparatus which is capable of efficiently reduicng noisepropagated to the outside.

[0025] In order to achieve the above-mentioned objects, a compressorhaving a noise reducing apparatus includes a sealed casing having amulti-wall structure formed at least at a certain portion thereof andfilled with a fluid between walls of the multi-wall.

[0026] An oil inflow path is formed at the multi-wall to make oil filledin the casing flow between the walls of the multi-wall.

[0027] The casing has a multi-wall structure at the bottom surface.

[0028] In an embodiment of the present invention, a bulkhead isadditionally formed at the bottom surface of the casing to construct adouble-wall structure.

[0029] In another embodiment of the present invention, a base is formedat the bottom portion of the casing to construct a multi-wall structure,and a fluid is filled in a space between the casing and the base.

[0030] The compressor in accordance with an embodiment of the presentinvention includes an electric motor part placed at the internal upperportion of the casing and generating a rotational force and acompressing part placed at the internal lower portion of the casing,compressing and discharging the fluid by the rotational force generatedin the electric motor part.

[0031] The compressor in accordance with another embodiment of thepresent invention includes an electric motor part placed at the internallower portion of the casing and generating a rotational force and acompressing part placed at the internal upper portion of the casing,compressing and discharging the fluid by the rotational force generatedin the electric motor part.

[0032] In addition, a compressor having a noise reducing apparatus inaccordance with the present invention includes a sealed casing having acylindrical body, an upper cap combined with the upper portion of thebody, a lower cap combined with the lower portion of the body and abulkhead placed inside the lower cap to construct a multi-wall with thelower cap.

[0033] An oil inflow path is formed at the bulkhead to make the oilinside the casing flow and fill therein.

[0034] In an embodiment of the present invention, the bulkhead issupported by the lower cap by projecting plural protrusions.

[0035] A ratio (d/t₁) of a distance (d) between the casing and thebulkhead to a casing thickness (t1) is within the range of 0.0˜3.0.

[0036] In another embodiment of the present invention, thecircumferential surface of the bulkhead is fixed to the internal wall ofthe lower cap.

[0037] In further embodiment of the present invention, thecircumferential surface of the bulkhead is separated from the lower capand supported by the lower cap through a supporting rod.

[0038] The bulkhead is made of a material different from that of thelower cap.

[0039] A space between the lower cap and the bulkhead is in a vacuumstate.

[0040] A noise reducing member is inserted between the lower cap and thebulkhead.

[0041] In order to achieve the above-mentioned objects, a compressorhaving a noise reducing apparatus in accordance with the presentinvention includes a sealed casing having a multi-wall structure atleast at a certain portion; a cylinder assembly placed inside the casingand having a suction path and a discharge path; a Z-plate dividing theinternal space of the cylinder assembly into plural compressing spaces,sucking, compressing and discharging the fluid while being rotating byan electric motor part; and plural vanes for dividing each compressingspace into a suction region and a compression region while performing areciprocating motion by contacting to the both surfaces of the Z-plate.

[0042] In addition, in order to achieve the above-mentioned objects, acompressor having a noise reducing apparatus in accordance with thepresent invention includes a sealed casing having a multi-wall structureat least a certain portion; a cylinder assembly placed inside the casingand having a suction path and a discharge path; a Z-plate dividing theinternal space of the cylinder assembly into plural compressing spaces,sucking, compressing and discharging the fluid while being rotating byan electric motor part; plural vanes for dividing each compressing spaceinto a suction region and a compression region while performing areciprocating motion by contacting to the both surfaces of the Z-plate;and a noise insulating means placed inside the casing and insulatingnoise propagated to the outside of the casing.

[0043] The noise insulating means is constructed by forming a multi-wallstructure at least at a certain portion of the sealed casing.

[0044] In the compressor having a noise reducing apparatus in accordancewith the present invention, it is capable of minimizing noise propagatedto the outside of the casing, in particular, by constructing the bottomcap of the casing as the double wall structure and naturally filling oilinside the casing into the double wall, high frequency noise occurred atthe bottom cap side can be efficiently excluded, and accordingly a noiseinsulation efficiency can be maximized.

BRIEF DESCRIPTION OF DRAWINGS

[0045] The accompanying drawings, which are included to provide afurther understanding of the invention and are incorporated in andconstitute a part of this specification, illustrate embodiments of theinvention and together with the description serve to explain theprinciples of the invention.

[0046] In the drawings:

[0047]FIG. 1 is a longitudinal sectional view illustrating the priorZ-compressor;

[0048]FIG. 2 is a radiation distribution view illustrating a level ofnoise propagated to the outside of a casing of the Z-compressor shown inFIG. 1;

[0049]FIG. 3 is a schematic sectional view illustrating a lower cap ofthe prior Z-compressor;

[0050]FIG. 4 is a graph illustrating a transmission loss according to athickness variation of the lower cap shown in FIG. 3;

[0051]FIG. 5 is a longitudinal sectional view illustrating aZ-compressor having a noise reducing apparatus according to a firstembodiment of the present invention;

[0052]FIG. 6 is a sectional view illustrating a lower cap of theZ-compressor shown in FIG. 5;

[0053]FIG. 7 is a plan view illustrating the lower cap shown in FIG. 6;

[0054]FIG. 8 are radiation distribution views respectively illustratinga level of noise propagated to the outside of a casing of theZ-compressor according to the prior art and the present invention;

[0055]FIG. 9 is a graph respectively illustrating a transmission loss ofa Z-compressor according to the prior art and the present invention;

[0056]FIG. 10 is a graph respectively illustrating a transmission lossaccording to a thickness variation of the lower cap and the bulkhead inaccordance with the prior art and the present invention;

[0057]FIG. 11 is a graph respectively illustrating a transmission lossaccording to a space between the lower cap and the bulkhead inaccordance with the prior art and the present invention;

[0058]FIG. 12 is a sectional view illustrating a modified lower caphaving a double wall of the Z-compressor in accordance with the firstembodiment of the present invention;

[0059]FIG. 13 is a sectional view illustrating a lower cap having adouble wall of a Z-compressor in accordance with a second embodiment ofthe present invention;

[0060]FIG. 14 is a sectional view illustrating a lower cap having adouble wall of a Z-compressor in accordance with a third embodiment ofthe present invention;

[0061]FIG. 15 is a sectional view illustrating a lower cap having adouble wall a Z-compressor in accordance with a fourth embodiment of thepresent invention; and

[0062]FIG. 16 is a longitudinal sectional view illustrating aZ-compressor in accordance with a fifth embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

[0063] Hereinafter, the preferred embodiments of the present inventionwill be described with reference to accompanying drawings.

[0064] To compare with the prior art, the preferred embodiments of thepresent invention will be described on the basis of a Z-compressor.However, the preferred embodiments are not limited by the Z-compressor,but rather should be construed broadly within its spirit and scope asdefined in the appended claims, and therefore all changes andmodifications that fall within the metes and bounds of the claims, orequivalence of such metes and bounds are therefore intended to beembraced by the appended claims.

[0065] FIGS. 5˜7 illustrate a Z-compressor in accordance with a firstembodiment of the present invention, FIG. 5 is a longitudinal sectionalview illustrating the Z-compressor, FIG. 6 is a sectional viewillustrating a lower cap of the Z-compressor, and FIG. 7 is a plan viewillustrating the lower cap of the Z-compressor.

[0066] As shown in FIG. 5, the Z-compressor having a noise reducingapparatus in accordance with the first embodiment of the presentinvention includes an electric motor part 60 placed at the internalupper portion of a sealed casing 50 and having a stator 62 and a rotor63 to generate a rotational force and a compressing part 70 placed atthe internal lower portion of the casing 50, sucking, compressing anddischarging a fluid by the rotational force generated in the electricpart 60.

[0067] Herein, the compressing part 70 includes a cylinder assembly 71having a first and a second bearing plates 73, 74, fixed inside thecasing 50 and having a suction path 72 a and a discharge path (notshown), a Z-plate 75 dividing the internal space of the cylinderassembly 71 into plural compression spaces, compressing and dischargingthe fluid while being rotated by the electric motor part 60, vanes 78,79 dividing each compression space V1, V2 into a suction region and acompression region in the rotation of the Z-plate 35 while performing areciprocation motion by respectively contacting to both surfaces of theZ-plate 75.

[0068] The electric motor part 50 and the compressing part 70respectively have the same or similar structure as those of the priorart.

[0069] However, the casing 50 includes a cylindrical body 51, an uppercap 52 combined with the upper portion of the body 51 by a weldingmethod, a lower cap 53 combined with the lower portion of the body 51 bya welding method and a bulkhead 55 placed inside the lower cap 53 toform a double wall structure with the lower cap 53, and accordingly ithas a different structure from that of the prior art.

[0070] In more detail, in order to prevent noise from being propagatedto the outside through the lower portion of the casing 50 in theoperation of the compressor, the bulkhead 55 is additionally installedto construct a sound insulation space K between the lower cap 53.

[0071] As shown in FIGS. 6 and 7, the lower cap 53 and the bulkhead 55respectively have a pan structure at which an upper portion is open andare combined each other, and accordingly a double wall structure isconstructed.

[0072] Naturally, so as to be inserted into the lower cap 53, the outerdiameter of the bulkhead 55 is the same as or smaller than the innerdiameter of the lower cap 53. Accordingly, the circumferential wallportion of the lower cap 53 and the bulkhead 55 are contacted eachother, and the bottom surface portions thereof maintain a certaindistance to construct a sound insulation space K.

[0073] Herein, because plural protrusions 55 a are projected from thebulkhead 55 and support the bottom surface of the lower cap 53, acertain space between the lower cap 53 and the bulkhead 55 can bemaintained.

[0074] It is preferable to form not less than three protrusions tosecure a stable supporting structure.

[0075] In addition, plural oil inflow holes 55 b are formed at thebulkhead 55 to make oil inside the casing 50 flow and fill in the soundinsulation space K. Accordingly, the oil inside the casing 50 naturallyflows in and fills the sound insulation space K between the lower cap 53and the bulkhead 55 through the oil inflow holes 55 b.

[0076] In the meantime, in the first embodiment of the presentinvention, only the lower cap 53 has the double wall structure in thecasing 50, however, it is also possible to construct the body 51including the lower cap 53 or the upper cap 52 as a double wailstructure according to compressor design conditions.

[0077] In addition, in the first embodiment of the present invention,the lower cap 53 has the double wall structure in the casing 50,however, it is also possible to construct the lower cap 53 to have athree or a four-wall structure.

[0078] The operation and advantages of the Z-compressor in accordancewith the first embodiment of the present invention will be describedwith reference to accompanying FIGS. 8˜11.

[0079]FIG. 8 are radiation distribution views respectively illustratinga level of noise propagated to the outside of a casing of theZ-compressor according to the prior art and the present invention;

[0080] As depicted in FIG. 8, noise propagated to the outside of thecasing 50 in the Z-compressor (B) according to the present invention issignificantly reduced in comparison with that of the prior Z-compressor(A). In the test result, generally noise propagated to the outside isreduced about 3˜4 dB, it means sound insulation performance is improved.

[0081] In particular, in the Z-compressor (B) according to the presentinvention, high frequency noise mainly propagated from the lower capportion of the casing 50 is dramatically reduced.

[0082]FIG. 9 is a graph respectively illustrating a transmission loss ofthe Z-compressor according to the prior art and the present invention.In comparison with the prior Z-compressor including the lower cap havinga single-wall structure as the prior art, in the Z-compressor includingthe lower cap having the double-wail structure according to the presentinvention, sound insulation performance (transmission loss) is improvedabout 30 dB at the frequency region (D) at which a propagated noisequestion is raised, and accordingly a noise reducing efficiency of thecompressor can be maximized.

[0083] Particularly, in the present invention, because oil inside thecasing 50 naturally fills the sound insulation space K between the lowercap 53 and the bulkhead 55 for lubrication and cooling, a resonancefrequency generated in the sound insulation space K between the lowercap 53 and the bulkhead 55 can be reduced, and accordingly oil insidethe casing 50 can perform a sound insulation function. Accordingly,propagation noise generated in the operation of the compressor can beefficiently reduced with the simple structure.

[0084] In the meantime, FIG. 10 is a graph respectively illustrating atransmission loss according to a thickness variation of the lower capand the bulkhead in accordance with the prior art and the presentinvention. P is a graph illustrating variation of a sound insulationquantity according to a noise frequency variation when a thickness ofthe lower cap having the single wall as the prior art is 3.2 t. A, B andC are graphs illustrating variation of a sound insulation quantityaccording to a noise frequency variation when a ratio (t₂/t₁) of abulkhead thickness (t₂) to a casing thickness (t₁) as the presentinvention is respectively 0.1, 0.3 and 1.

[0085] In the test results shown in the comparison graph, the more athickness difference between the lower cap thickness and the bulkheadthickness, the more a transmission loss is increased, and accordingly asound insulation efficiency can be improved. Accordingly, it ispreferable to have a ratio (t₂/t₁) of a bulkhead thickness (t₂) to acasing thickness (t₁) place within the range of 0.01˜2.0.

[0086] Next, FIG. 11 is a graph respectively illustrating a transmissionloss according to a distance variation of the lower cap and thebulkhead. P is a graph illustrating variation of a sound insulationquantity according to a noise frequency variation when a thickness ofthe lower cap having the single wall as the prior art is 3.2 t. B₁, B₂and B₃ are graphs respectively illustrating variation of a soundinsulation quantity according to a noise frequency variation when adistance (d) between the casing and the bulkhead is 0 mm, 2 mm and 3 mmon condition that a ratio (t₂/t₁) of a bulkhead thickness (t₂) to acasing thickness (t₁) is 0.3.

[0087] In the test results shown the comparison graphs, the more adistance (d) between the casing and the bulkhead is increased, the moresound insulation efficiency can be improved. Accordingly, in the presentinvention, a ratio (d/t₁) of a distance (d) between the casing and thebulkhead to a casing thickness (t₁) is within the range of 0.0˜3.0.

[0088]FIG. 12 is a sectional view illustrating a modified lower caphaving a double wall of the Z-compressor in accordance with the firstembodiment of the present invention. In comparison with the lower capshown in FIG. 6, in a lower cap 53′ and a bulkhead 55′, a height of eachside wall 53 a, 55 a is increased as ‘E’ toward the internal space ofthe body 51′.

[0089] Accordingly, because the combined region of the lower cap 53′ andthe body 51′ is increased as ‘E’ height, also noise propagated throughthe lower portion of the body 51′ can be insulated.

[0090]FIG. 13 is a sectional view illustrating a lower cap having adouble wall of a Z-compressor in accordance with a second embodiment ofthe present invention.

[0091] In the above-described first embodiment, protrusions are formedat the bulkhead and supported by the lower cap. However, in the secondembodiment of the present invention, protrusions are not formed, theside wall portion as the circumferential surface of a bulkhead 155 iswelded and fixed to the internal wall of a lower cap 153.

[0092] And, plural oil inflow holes 155 a are formed at the bulkhead 155to make oil inside the compressor flow in the compressor.

[0093]FIG. 14 is a sectional view illustrating a lower cap having adouble wall of a Z-compressor in accordance with a third embodiment ofthe present invention.

[0094] In the third embodiment of the present invention, the outercircumference of a bulkhead 255 is separated from the internal wall of alower cap 253 to have a certain distance and is supported by the lowercap 253 through a supporting rod 260.

[0095] Herein, the supporting rod 260 has a ring shape and forms a spaceK′ between the lower cap 253 and the bulkhead 255, the space K′ can beconstructed as a sealed-vacuum structure or a gas-filled structure.

[0096] In addition, by inserting a sound insulation material such as aglass wool and a rock wool, etc. or a rigid fabric inside the space K′,a transmission loss can be improved.

[0097] Of course, oil inside the compressor flows in the outercircumference of the space K′ to insulate noise propagated to theoutside.

[0098]FIG. 15 is a sectional view illustrating a lower cap having adouble wall of a Z-compressor in accordance with a fourth embodiment ofthe present invention.

[0099] In the above-described other embodiments of the presentinvention, a bulkhead is installed inside a lower cap. However, in thefourth embodiment of the present invention, a base 355 connected to asupporting rod 360 is formed at the bottom portion of a lower cap 353 toconstruct a multi-wall structure. And, because plural oil inflow holes353 a are formed at the lower cap 353 to make oil flow in the spacebetween the base 355, a fluid is filled in the space between the lowercap 353 and the base 355, and accordingly a propagated noise can beinsulated.

[0100]FIG. 16 is a longitudinal sectional view illustrating aZ-compressor in accordance with a fifth embodiment of the presentinvention.

[0101] In the Z-compressor according to the first embodiment of thepresent invention, an electric motor part is placed at the upper portionof the casing, a compressing part is placed at the lower portion.However, in the Z-compressor according to the fifth embodiment of thepresent invention, an electric motor part 460 generating rotationalforce is placed at the internal lower portion of a casing 450, and acompressing part 470 compressing a fluid by the rotational forcegenerated in an electric motor part 460 and discharging it is placed atthe internal upper portion of the casing 450.

[0102] And, the duublel-wall structure at the lower portion of thecasing 450 can be variously formed according to the above-describedfirst˜fourth embodiments.

[0103] In the meantime, in the present invention, because a material ofa bulkhead is also major factor for determining propagated noiseinsulation performance, the same material as a lower cap can be used asa material of the bulkhead, and it is also possible to form a bulkheadwith a material different from that of the lower cap.

INDUSTRIAL APPLICABILITY

[0104] In a compressor having a noise reducing apparatus in accordancewith the present invention, by forming a certain portion of a casing asa multi-wall structure, noise propagated to the outside of the casingcan be minimized.

[0105] In addition, in a compressor having a noise reducing apparatus inaccordance with the present invention, by efficiently insulating highfrequency noise mainly propagated from a lower cap side of a compressor,a noise reducing quantity of the compressor can be maximized.

[0106] In particular, in a compressor having a noise reducing apparatusin accordance with the present invention, with a simple structure formaking oil inside a casing naturally fill a space between a dual wall,propagated noise occurred in the operation of the compressor can beefficiently reduced.

[0107] In addition, in a compressor having a noise reducing apparatus inaccordance with the present invention, noise propagated from acompressing part of a compressor using a Z-plate to the outside of acasing can be efficiently reduced.

[0108] A compressor having a noise reducing apparatus in accordance withthe present invention can be applied to not only a Z-compressor but alsoa reciprocating compressor, a scroll type compressor, a centrifugalcompressor and a rotation type compressor, etc.

[0109] In addition, a compressor having a noise reducing apparatus inaccordance with the present invention can be easily applied to arefrigerator and an air conditioner, etc. using a refrigerating cycleconsisting of a compressor, a condenser, an expansive valve and anevaporator. Accordingly, when a compressor having a noise reducingapparatus in accordance with the present invention is applied to arefrigerator or an air conditioner, by minimizing noise occurred in theoperation of the refrigerator or air conditioner, a reliability of theproduct can be improved, and also calm and pleasant circumstances can beachieved.

1. A compressor having a noise reducing apparatus, comprising; a sealedcasing having a multi-wall structure formed at least at a certainportion thereof and filled with a fluid between walls of the multi-wall.2. The compressor of claim 1, wherein the fluid filled between themulti-wall is gas.
 3. The compressor of claim 1, wherein the fluidfilled between the multi-wall is a liquid.
 4. The compressor of claim 1,wherein an oil inflow path is formed at the multi-wall to make oilfilled in the casing flow between the walls of the multi-wall.
 5. Thecompressor of claim 1, wherein the casing has a multi-wall structure atthe bottom surface.
 6. The compressor of claim 5, wherein a bulkhead isadditionally formed at the bottom surface of the casing to construct adouble-wall structure.
 7. The compressor of claim 6, wherein an oilinflow path is formed at the bulkhead to make oil filled in the casingflow therein.
 8. The compressor of claim 1, wherein a base is positionedat the bottom portion of the casing to construct a multi-wall structure,and a fluid is filled in a space between the casing and the base.
 9. Thecompressor of claim 8, wherein an oil inflow path is formed at thecasing to make oil flow in the space between the casing and the base.10. The compressor of claim 1, wherein the compressor includes anelectric motor part placed at the internal upper portion of the casingand generating a rotational force and a compressing part placed at theinternal lower portion of the casing, compressing and discharging thefluid by the rotational force generated in the electric motor part. 11.The compressor of claim 1, wherein the compressor includes an electricmotor part placed at the internal lower portion of the casing andgenerating a rotational force and a compressing part placed at theinternal upper portion of the casing, compressing and discharging thefluid by the rotational force generated in the electric motor part. 12.The compressor of claim 1, wherein the compressor includes: acompressing part for compressing and discharging the fluid by therotational force generated in an electric motor part; wherein thecompressing part consists of a cylinder assembly fixed inside the casingand having a suction path and a discharge path, a Z-plate dividing theinternal space of the cylinder assembly into plural compressing spaces,sucking, compressing and discharging the fluid while being rotated bythe electric motor part, and plural vanes for dividing each compressingspace into a suction region and a compression region while performing areciprocating motion by contacting to the both surfaces of the Z-plate.13. A compressor having a noise reducing apparatus, comprising: a sealedcasing having a cylindrical body, an upper cap combined with the upperportion of the body, a lower cap combined with the lower portion of thebody and a bulkhead placed inside the lower cap to construct amulti-wall with the lower cap.
 14. The compressor of claim 13, whereinan oil inflow path is formed at the bulkhead to make the oil inside thecasing flow and fill therein.
 15. The compressor of claim 13, whereinthe bulkhead is supported by the lower cap by projecting pluralprotrusions.
 16. The compressor of claim 13, wherein the circumferentialsurface of the bulkhead is fixed to the internal wall of the lower cap.17. The compressor of claim 13, wherein a ratio (t₂/t₁) of a bulkheadthickness (t₂) to a casing thickness (t₁) is within the range of0.01˜2.0.
 18. The compressor of claim 13, wherein a ratio (d/t₁) of adistance (d) between the casing and the bulkhead to a casing thickness(t1) is within the range of 0.0˜3.0.
 19. The compressor of claim 13,wherein the circumferential surface of the bulkhead is separated fromthe lower cap and supported by the lower cap through a supporting rod.20. The compressor of claim 13, wherein the bulkhead is made of amaterial different from that of the lower cap.
 21. The compressor ofclaim 13, wherein a space between the lower cap and the bulkhead is in avacuum state.
 22. The compressor of claim 13, wherein a noise reducingmember is inserted between the lower cap and the bulkhead.
 23. Thecompressor of claim 13, wherein the lower cap and the bulkhead have apan structure at which the upper portion is open and are combined eachother.
 24. A compressor having a noise reducing apparatus, comprising: asealed casing having a multi-wall structure at least at a certainportion; a cylinder assembly placed inside the casing and having asuction path and a discharge path; a Z-plate dividing the internal spaceof the cylinder assembly into plural compressing spaces, sucking,compressing and discharging the fluid while being rotating by anelectric motor part; and plural vanes for dividing each compressingspace into a suction region and a compression region while performing areciprocating motion by contacting to the both surfaces of the Z-plate.25. The compressor of claim 24, wherein a space between multi-wall ofthe casing is in a vacuum.
 26. The compressor of claim 24, wherein afluid is filled in a space between the multi-wall of the casing.
 27. Thecompressor of claim 24, wherein a noise reducing member is placedbetween the multi-wall of the casing.
 28. The compressor of claim 24,wherein the casing has a multi-wall structure at the bottom portion. 29.The compressor of claim 24, wherein a bulkhead is added to the bottomsurface of the casing to construct a double-wall structure.
 30. Thecompressor of claim 29, wherein an oil inflow path is formed at thebulkhead to make the oil inside the casing flow and fill therein.
 31. Acompressor having a noise reducing apparatus, comprising: a sealedcasing having a multi-wall structure at least a certain portion thereof;a cylinder assembly placed inside the casing and having a suction pathand a discharge path; a Z-plate dividing the internal space of thecylinder assembly into plural compressing spaces, sucking, compressingand discharging the fluid while being rotating by an electric motorpart; plural vanes for dividing each compressing space into a suctionregion and a compression region while performing a reciprocating motionby contacting to the both surfaces of the Z-plate; and a noiseinsulating means placed inside the casing and insulating noisepropagated to the outside of the casing.
 32. The compressor of claim 31,wherein the noise insulating means is constructed by forming amulti-wall structure at least at a certain portion of the sealed casing.33. In a refrigerator using a refrigerant cycle including a compressor,a condenser, an expansive valve and an evaporator, the compressorcomprising: a sealed casing having a multi-wall structure at least at acertain portion thereof and filled with a fluid in a space between wallsof the multi-wall.
 34. The refrigerator of claim 33, wherein an oilinflow path is formed at the multi-wall to make the oil inside thecasing flow and fill in a space between the walls of the multi-wall. 35.In an air conditioner using a refrigerant cycle including a compressor,a condenser, an expansive valve and an evaporator, the compressorcomprising: a sealed casing having a multi-wall structure at least at acertain portion thereof and filled with a fluid in a space between wallsof the multi-wall.
 36. The air conditioner of claim 35, wherein an oilinflow path is formed at the multi-wall to make the oil inside thecasing flow and fill in a space between the Walls of the multi-wall.